Remember, National Pi Day is March 14! That's 3/14.
Dr. Math has a great FAQ page on pi. Check out The Joy of Pi links to pi pages on the web.
Kellie Kutkey made Apple Pi in March 2001 to hang in her Portland, Oregon classroom. It is 22" by 22" (the quilt, not the classroom).
While similar to Mona Wilkerson's Traditional as Apple Pi (below), the two quilts were created independently. If the two quilts were set side by side, one might wonder what 2 pi are. (Humor flag: 2 pi r is 2 times pi times the circle radius, i.e., the circumference.)
Mona Wilkerson made Traditional as Apple Pi in response to a quilt challenge by National Online Quilters in the spring of 1998. It is 24" by 24" because, as she writes, "I just knew that pi had to be square."
Sharon Benton of Redmond, WA made Pi Are Square, an original design inspired by Gayle Bryan's challenge class in March 1998. The theme for this challenge was Circles and Squares. Sharon says she works as a Technical Editor, but plays as a quilter! She has been quilting for 4 years and enjoys creating original contemporary designs. Pi Are Square is 32-1/2" by 18", and is machine pieced and quilted.
Sharon explained how she printed the fabric using an inkjet printer. To stabilize the fabric, she ironed it to freezer paper, then trimmed it to 8.5 x 11". The three panels were printed twice directly to fabric using an inkjet printer. The first pass she printed in gold the first 200 digits of Pi. Then she printed the two panels on each end a second time -the left with the formula for squaring a circle and the right with a definition of Pi. The border is made of random scraps of fabric and quilted with the Pi symbol and various formulas.
Sharon said, "Making this quilt was quite an adventure - I met Pi enthusiasts from all over the world via email and learned a lot along the way."